smallinvoice MCP by usefulapi

smallinvoice MCP by usefulapi

Live endpoint: https://smallinvoice.usefulapi.io/mcp · Homepage: https://usefulapi.io/smallinvoice

Connect

• Claude (claude.ai, Desktop): open Customize → Connectors, click + Add → Add custom connector, and paste https://smallinvoice.usefulapi.io/mcp.
• Claude Code: claude mcp add --transport http smallinvoice https://smallinvoice.usefulapi.io/mcp, then run /mcp to log in.
• VS Code: Add to VS Code.
• Cursor and other clients: add the URL as a remote MCP server:

{
  "mcpServers": {
    "smallinvoice": {
      "url": "https://smallinvoice.usefulapi.io/mcp"
    }
  }
}

Add only the URL. Do not add an Authorization header or an API key to the client config: the server signs you in with OAuth, and the login page asks for your smallinvoice credentials.

Step-by-step setup, where to find your credentials, and FAQ: https://usefulapi.io/smallinvoice/

Tools

Tool	Type	What it does
smallinvoice_get_owner	read	Get the account owner
smallinvoice_list_contacts	read	List contacts
smallinvoice_get_contact	read	Get a contact
smallinvoice_list_contact_addresses	read	List a contact's addresses
smallinvoice_list_contact_people	read	List a contact's people
smallinvoice_list_contact_groups	read	List contact groups
smallinvoice_list_invoices	read	List invoices
smallinvoice_get_invoice	read	Get an invoice
smallinvoice_list_invoice_payments	read	List payments of an invoice
smallinvoice_list_offers	read	List offers
smallinvoice_get_offer	read	Get an offer
smallinvoice_list_order_confirmations	read	List order confirmations
smallinvoice_get_order_confirmation	read	Get an order confirmation
smallinvoice_list_delivery_notes	read	List delivery notes
smallinvoice_get_delivery_note	read	Get a delivery note
smallinvoice_list_products	read	List catalog products
smallinvoice_list_services	read	List catalog services
smallinvoice_list_units	read	List units
smallinvoice_list_bank_accounts	read	List bank accounts
smallinvoice_list_projects	read	List projects
smallinvoice_get_project	read	Get a project
smallinvoice_list_working_hours	read	List working hours
smallinvoice_list_efforts	read	List efforts
smallinvoice_list_activities	read	List activities
smallinvoice_list_cost_units	read	List cost units
smallinvoice_create_contact	write	Create a contact
smallinvoice_create_invoice	write	Create an invoice
smallinvoice_usage_status	meta	Usage status (free-tier meter)
smallinvoice_request_feature	meta	Request a missing feature
smallinvoice_upgrade	meta	Upgrade to Pro (unlimited*)
smallinvoice_cancel_subscription	meta	Cancel the Pro subscription

read tools are read-only; write tools mutate data (clients should confirm them); meta tools report usage, manage your subscription or send a feature request.

Pricing

Plan	Price	Limit
Free	$0	50 tool calls / month
Pro (per account)	$9/mo or $90/yr (2 months free)	Unlimited*

*Pro has a fair use limit of 10,000 tool calls a month on this server. For more, write to [email protected].

Pro covers this server only. Subscribe with smallinvoice_upgrade (it returns a Stripe Checkout link). Cancel any time with smallinvoice_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running smallinvoice_upgrade before then undoes the cancel. Or write to [email protected].

License